Focal nodular Hyperplasia

I had an abdominal ultrasound which came back as an enlarged liver  - Focal Nodular Hyperplasia.  I have to go for a CT scan and perhaps have biopsy done. I am 45 years old and it was through a routine check that this was picked up.  I have recently been on prognova hrt for 2 months.  I have a couple of glasses of wine at night. My ggt level was 103 and cholesterol 6.94.  Can you tell me what cause FNH is do you have to have surgery for it or can medication be given.  I am rather nervous about it all.